1. Field of the Invention
The present invention relates to a method for controlling a play speed in an optical disc device in order to variably control the play speed in a sequential play mode for sequentially reading and reproducing A/V data recorded on an optical disc such as a CD or DVD.
2. Discussion of the Related Art
Recently, optical discs capable of recording a large quantity of high-quality audio and video data, such as CDs or DVDs, have been developed and made commercially available. In association with such optical discs, optical disc devices such as CD players or DVD players have also been developed and made commercially available.
Where a sequential play operation for sequentially reading and reproducing A/V data recorded on an optical disc is carried out at the request of a user, the optical disc device first temporarily stores A/V data read from the optical disc in a buffer included in the optical disc device, and then reproduces the temporarily stored A/V data at a data transfer rate corresponding to a basic speed (1×).
On the other hand, where the A/V data recorded on the optical disc is read at a higher speed, for example, an 8× speed (8 times of the basic speed), an overflow of data occurs in the buffer because the rate of data inputted to the buffer is an 8× speed whereas the rate of data outputted from the buffer is a 1× speed. At this time, the optical disc device pauses the operation of reading the A/V data recorded on the optical disc, and again reads the A/V data recorded on the optical disc from the pause position after a predetermined time elapses or when the amount of data temporarily stored in the buffer is reduced to a predetermined reference value or below. Thus, the operation of storing data in the buffer is repeatedly carried out.
Although the operation of reading the A/V data recorded on the optical disc is paused to prevent the overflow of data from occurring in the buffer, and then again performed from the pause position, the reading of data from the optical disc may fail at the re-start of the reading operation due to defects generated at the pause position during a search for the pause position. In this case, re-attempts are made to read data from the pause position on the optical disc. When the number of re-attempts reaches a predetermined value, the data reading is re-attempted at a lower speed.
In this case, the data reading may be possible because data can be read from the optical disc at a low speed in general cases. However, at some point, outputting of reproduced audio and video signals from the buffer may be temporarily stopped because the data in the buffer may be under-run due to the read re-attempts and speed reduction.